Animal Skyways

Canada’s most-travelled highway tears through the country’s oldest national park, imperiling both humans and wildlife. But park administrators came up with an inspired solution:

They look, for the most part, like typical pedestrian infrastructure: elliptical or boxy concrete culverts under the highway high enough for a human to pass through, or overpasses that would look entirely familiar to the vehicles passing below. All this highway engineering, though, is meant for the benefit of bears. And cougars, and wolves, and elk. …

[O]ver the years, critics and transportation planners, even some environmentalists have groused about the idea: Taxpayer money, building overpasses for bears? Is that really necessary? Would they even use the things? Researchers have been methodically studying the crossings since 1996 to answer this. And it turns out that, yes, animals deterred by fencing that now runs the full 70-kilometer [43.5-mile] length of the highway in the park actually cross the road an awful lot like a rational pedestrian would. It takes them a while, though, to adapt to the crossings after a new one is constructed: about four to five years for elk and deer, five to seven years for the large carnivores.